Researchers have a new theory about why sea mammals grow to such huge proportions. Blue Whales can grow to be longer than an NBA court and over 400,000 pounds. It has long been thought that they grow this large by chance but there may be some other explanation for this.
William Gearty of Stanford School of Earth explains:
"We went in just looking to statistically show that aquatic mammals are larger than we would expect by chance,"
"While we did find that," he added, "we also came away with surprising new knowledge that these mammals are actually under really strong evolutionary pressures, much stronger than those on land, which goes against the expectations of many hypotheses regarding why these animals have gotten so big."
Every known sea mammal appears to have had ancestors that originated on land. Seals and sea lions are closely related to dogs. Manatees are more closely related to elephants. Whales and dolphins are like hippos.
Researchers found that once the animals switched to the sea they began to change very rapidly.
Gearty goes on:
"Since mammals are warm-blooded, we need to maintain relatively high internal body temperatures," Gearty said. "Once mammals enter the water, this becomes an even harder process, and the only way to counteract this pressure is to get larger to reduce the relative amount of energy you lose to the water around you."
